Heat and pressure resisting tools



15,1931. F. SINGER HEAT AnD PRESSURE RESISTI'NG TOOLS Filed July 10, 1930 Il'," W

- INVENTOR witnesses haw.

Patented Dec. s, 1931 UNITED STATES FRITZ STNGER, O1 lNUBEHBEBG, GEBIANY HEAT m PRESSURE RISISTING TOOLS Application filed July 10, 1930, Serial No. 487,116, and in Germany July 2, 1928.

My invention pertains to ring-shaped tools (WhlCll term is intended to include ring shaped tool and machine parts) such as are required to resist the stresses resulting from 5 the high temperatures and high pressures en-' countered in carryingout the hot extrusion process. The invention is particularly applicable to tools such as are employed 1n the hot extrusion of tubes and solid shapes,

especially from hard and semi-hard metals such, for instance, as brass and steel.

Tools used under the conditions above referred to, and particularly in the extrusion of hard and semi-hard metals, are subject to 1;, more or less rapid deterioration, and, it has been found that this deterioration is less due to wear than to the formation of cracks resulting from the violent changes of temperature and pressure to which the tools are subjected. It is a major object of myinvention to obviate this deterioration of the tools by the formation of cracks therein. A further object of my invention is to facilitate,

and in some cases for the first time render possible, the production of tools of this character from metal alloys and compounds, which, by reason of their special strength, wear resisting properties, etc.,- are desirable for the purpose, but which (because of the conditions requiring to be met in producing them) either cannot be produced, or can only be produced with great difliculty, otherwise than in relatively small pieces.

I attain the above objects by making the required tool of composite form, it bein composed of a plurality of sections the num r of which corresponds, as closely as it may within the limits of economical manufacture, with the number of cracks which manifest them- 4 selves in the use ofa tool which is similar but made in one-piece. As one example, a matrix die ring. for use in extrusion ismade up from a plurality of segments arranged as in the commutator of a dynamo, these segments bein secured in position, as, for instance, by s rinking upon them an outer .ring a or aring-shaped portion of the matrix die body. Tools ofgreater"length,as, for exam Ie, the inner bushings of containers from whlch metal is'to be extruded,-may becomplanes of engagement of the sections therethe illetbearing ring a; and, if desired, this ring also mast; be composed of a plurality of take still other forms than those shown, without exceeding the scope of the invention as defined in the appended claims.

In the drawings Fig. 1 is a sectional elevation of a simple form of matrix die ring constructed in ac-- cordance with my invention, shown as mounted, by shrinking, in a recess of a die body and as having a billet bearing ring associated with it;

Fig. 2 isa section on the line II-II of Fig. 1; V

Fig. 3 is a view similar to Fig. 1 but showing the matrix die ring as constituted by a plurality of rings (in this-case two) the sections of each ring being staggered with relation to those of the adjacent ring; and

Fig. 4 is a View similar to Fig. 1, but showing a form of matrix die ring in which the of are oblique to planes radial to the axis of the ring.

Referring now to Figs. 1 and 2, a represents the matrix die ring, which is the member of the matrix die that is subjected to the greatest stresses. This 'die ring is composed of a plurality of segments a arranged in a similar manner to the segments of a commutator. vThough the sections a may be retained in position other ways, they are shown as secured upon the die body 6 by being shrunk within the wall I) of an annular recess formed in the top'of the die body.

U on the die body and die ring is mounted so cuts, in cated at 0'.

n Fig. 3 there shownan embodiment of my invention in which the matrix die ring is constituted by two rings d and e superposed 300 one on the other though more than two might be used if found desirable. The rings at and e are made up of sections, (1 and e, as before, but the sections of one ring are staggered with respect to those of the other ring. Thus should wear and tear deteriorate the rings at the lines where their sections adjoin one another, the opportunity for such deterioration to manifest itself in the form of lines on the extruded product is minimized, and the useful life of the matrix die ring is thereby lenlgthened.

In i 4 the matrix die ring is shown as constituted by but one ring, as in Figs. 1 and 2, such ring being designated in that figure as 7; but the sections f are so shaped that their meeting faces are oblique to planes extending radially from the axis of the ring. In this way deterioration of the ring at the lines where its sections adjoin one another is minimized, and, in any case, the formation of lines u on the extruded material, due to such deterioration, is prevented.

I may use such materials as chill castings, stellites, fritted carbides of Wolfram, as Widia metal, steels having a high percentage of Wolfram, and the like, in making the segments, and am enabled by my invention to obtain the benefit of their great hardness and resistance to wear and tear without sufi'ering the drawback that cracks are liable to. appear in the tool because of the brittleness which inevitably characterizes such materials.

A further advantage of my inevention lies in the fact that by it I am enabled to produce relatively large tools from compounds of heavy metals, such as fritted carbides of wolfram, which heretofore it has only been possible to produce in relatively small pieces. For instance, the fritted' carbide known as Widia metal is of exceptional hardness, but because of limitations encountered in its manufacture, it has not been possible to produce it in pieces of large size. The desired qualities of this and kindred metals become available to a greatly increased extent as a result of my invention.

I claim:

1. A ring-shaped hot extrusion die comprising a composite member made up of a plurality of sections of heat and pressureresisting metal, said sections having their adjoining planes 'dis sed substantially lengthwise of such mem r, and an enclosing member surrounding said composite member to retain such sections solidly in position,

as and for the purposes set forth.

2. A ring-shaped hot extrusion die comprising a composite member made up of a plurality of sections of heat and pressurereslstmg metal, said sections having their adjoming planes disposed substantially radialto and in line with the axis oi such member,

and an enclosing member shrunk around said sections to retain them solidly in position, as and for the purposes set fort 8. A ring-shaped hot extrusion die comprising a composite member made up of a plurality of sections of heat and pressureresisting metal, said member being composed of a plurality of layers of sections, the sections in successive layers having their ad.- joining planes dis osed substantially lengthwise of such mem er and being disposed so that the planes of engagement of the sections of one layer are staggered with respect to the planes of engagement of those of the adjoining layer, and an enclosing member surroundlng said composite member to retain such sections solidly in position, as and for the purposes set forth. p

4. A ring-shaped hot extrusion die comprising a composite member made up of a plurality of sections of heat and pressureresisting metal, said sections having their adjoining planes disposed obli ue to the axis of such member, and an enc osing member surrounding said composite member to retain such sections solidly in position, as and for the purposes set forth.

In testimony whereof, I hereunto sign my name.

FRITZ SINGER. 

